RU2489659C1 - Rotary inclined furnace - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: furnace includes a lined bottle with two support rings, each of which is supported on two rollers, a burner screen with a gas injection burner fixed in it and provided with fourteen mixers, a receiving chute, a furnace rotation drive and a burner screen supply-discharge drive. The lined bottle has a heat insulating layer of two layers of flexible heat insulating fibre glass mullite silica cardboard and a layer of chamotte lightweight material, onto which a lining layer from mullite nonshrinking ramming compound is put. The burner includes an air flow rate control device, installed with an inclination of 15° to the bottle axis with possibility of gas supply to the burner along upper part of a turning column and a branch pipe. The furnace has an add-on receiving lined chute with handles, which is mounted on a trolley, a turning frame that is supported on front and rear pedestals when in operating position, on which the lined bottle is installed with possibility of being turned about the axis from the drive. The furnace can operate at natural and artificial thrust.

EFFECT: increasing furnace service life, reducing heat losses and hazardous emissions to atmosphere.

2 cl, 8 dwg

Description

The invention relates to ferrous metallurgy, and in particular to melting units for processing (remelting) non-ferrous metal waste, in particular for remelting secondary aluminum scrap and waste aluminum alloys into ingots and ingots. The furnace can be used for refining, producing alloys, averaging the chemical composition of scrap.

Known rotary melting furnace for processing non-ferrous metal waste: aluminum slag, aluminum chips and scrap (RF patent No. 2171437 C1), which is an analogue of the invention.

As well as the present invention, the analogue contains a lined flask with two support rings, each of which is supported by two rollers, a burner shield with a gas burner, a receiving chute, a furnace rotation drive and a burner inlet / outlet drive.

The disadvantages of this furnace are:

1. The charge is loaded through the loading hole, and the metal and slag are drained through the corresponding notches.

2. The absence of dust and gas cleaning, which would reduce the harmful effects on the environment.

3. There is no thermal insulation that would reduce heat loss to the environment.

4. Increased requirements for the dimensions of the feedstock, since the feed opening has limited dimensions.

Due to the above disadvantages, the furnace cannot solve the technical problem.

Also known device rotary melting furnace for the smelting of secondary aluminum (AS No. 875187), which is an analogue of the proposed furnace.

The rotary melting furnace described in the copyright certificate contains, like the proposed one, a lined flask (lined casing) with two support rings (bandages), each of which is supported by two rollers, gas burners, a rotary drive of the furnace and a filling window.

The disadvantages of this furnace are:

1. The release of molten metal is carried out with a stationary furnace through a drain hole located in the bottom of the melting chamber, which leads to a complication of the design.

2. Cleaning of the smelting chamber from iron pallets and slats is carried out both through the neck and through the filling window, which causes certain inconveniences (poor visibility and the need to have a window sill in the design).

3. The lack of dust and gas cleaning, which would reduce the harmful effects on the environment.

4. There is no thermal insulation that would reduce heat loss to the environment.

Due to the above disadvantages, the furnace cannot solve the technical problem.

The closest analogue (prototype) in relation to the inventive melting furnace is a rotary inclined furnace (RF patent No. 69975 for utility model), containing, like the claimed furnace, a lined flask with two support rings, each of which is supported on two rollers, a burner shield with gas burner, receiving chute, furnace rotation drive and burner shield drive-away. The prototype of the inventive furnace has the following disadvantages:

1. From the description it follows that the furnace is lined with conventional refractory fireclay bricks, so it has a relatively short service life.

2. The lack of dust and gas cleaning, which would reduce the harmful effects on the environment.

3. There is no thermal insulation that would reduce heat loss to the environment.

Due to the above disadvantages, the furnace cannot solve the technical problem.

The objective of the invention is the creation of a rotary inclined furnace for remelting non-ferrous metal waste, in particular, for remelting secondary aluminum scrap and waste aluminum alloys, which has a long service life, small heat loss to the environment due to special thermal insulation containing a dust and gas cleaning system, which allows to reduce emissions of harmful gases and dust into the atmosphere.

EFFECT: developed rotary inclined furnace has a long service life, small heat loss to the environment due to special thermal insulation, contains a dust and gas cleaning system, which allows to reduce emissions of harmful gases and dust into the atmosphere, which makes the process of remelting of secondary aluminum scrap and waste Aluminum alloy environmentally friendly.

The specified technical result is achieved due to the fact that in a rotary inclined furnace for processing non-ferrous metal wastes, containing a lined flask with two support rings, each of which is supported by two rollers, a burner shield with a gas burner, a receiving chute, a furnace rotation drive and a feed drive of the burner shield according to the invention, a heat-insulating layer is introduced into the lined flask, consisting of two layers of a flexible heat-insulating fiberglass mullite-siliceous cardboard and a layer w a lightweight motor weight onto which a lining layer of a mullite non-shrink packing material is stuffed with a crust crust, a gas injection burner mounted in a burner shield and having fourteen mixers, a divider containing an air flow control device with a slope of 15 ° to the axis is used as a burner device flasks and providing a flame 2.2 meters long when burning a gas-air mixture, gas is supplied to the burner along the upper part of the rotary column and nozzle, the rotary frame in the slave than the position rests on the front and rear curbstones, the lined flask is placed on the rotary frame and rotates around the axis from the drive, which includes: electric motor, gearbox, gear wheel, furnace, in addition, made with the possibility of working on natural and artificial traction with a dust and gas cleaning system to achieve an environmentally friendly process, which includes: a mixing chamber, a smoke exhaust, a gas treatment unit, and an ejector scrubber.

The introduced heat-insulating layer, consisting of two layers of flexible heat-insulating fiberglass mullite-siliceous cardboard and a layer of chamotte lightweight, laid on a phosphon, can reduce heat loss into the environment, and also allow you to additionally maintain the temperature of the metal in a rotary inclined furnace for processing non-ferrous metal waste (hereinafter referred to as the furnace) . The service life of the furnace is increased due to the use of mullite non-shrink packing material with a crust crust, which has high fire resistance and resistance.

Moreover, the proposed gas 14 mixing injection cylindrical burner having a divider heats the walls of the furnace well, heats the air in the furnace space and melts the charge. Mixers and a cast flame-stabilizing tunnel are made of ChX22 heat-resistant cast iron, and such divider parts as: axle, cone, nuts are made of VT18U titanium alloy. Titanium alloy for divider parts, heat-resistant cast iron, used as material for the manufacture of mixers, and a cast flame-stabilizing tunnel, can increase the life of the burner and, of course, the furnace. The burner has in its design a device for regulating air flow, which allows it to be used for various compositions of natural gases. Nominal thermal power of the proposed burner is 1.9 MW.

It is important to note that the furnace has a mounted on the trolley mounted receiving lined trough with handles, which moves on the trolley along the rails to the lined flask and vice versa using a hydraulic cylinder.

At the same time, the rotary inclined furnace for processing non-ferrous metal waste is made with the possibility of working on natural and artificial traction with a dust and gas cleaning system, and the gas cleaning unit has a wide range of purification of harmful substances contained in flue gases, dust is cleaned in the ejector scrubber. Harmful substances in flue gases are adsorbed by adsorbent: hydrated lime, silica gel, birch and activated carbon. Natural draft work is carried out if the dimensions of the sanitary protection zone allow, as well as during repair and maintenance work at the dust and gas cleaning installation. Introduction to the furnace design of the above devices, materials, etc. provides a solution to the problem.

It should be noted that it is necessary to load scrap into the melting furnace, crushed by a grinder (shredder) and passed magnetic separation. In the design part of the application for an invention is depicted:

figure 1 - view of the furnace and installation of gas and dust cleaning in plan;

figure 2 is a side view of the furnace and dust removal installation;

figure 3 is a view And the furnace (side);

figure 4 is a view B of the furnace (from the side of the loading window);

figure 5 - lining of the furnace in the context;

Fig.6 is a view of a gas injection burner from the side of the air flow regulator;

in Fig.7 - gas injection burner section BB;

on Fig - gas injection burner section GG.

The proposed rotary inclined furnace for processing non-ferrous metal waste, mainly aluminum scrap and waste aluminum alloys

has a front 1 and rear 2 pedestals that are attached to the furnace foundation with eight anchor bolts (not shown). On the foundation of the furnace

installed: right 3 and left 4 hinge supports, right 5 and left 6 hydraulic cylinder rods 7 of the furnace lifting mechanism, in addition, a column 8 of the burner shield turning mechanism (pos. 3 and 4 in FIG. 4) is attached to the foundation with four anchor bolts (not shown) No. 3 are symmetrical poses No. 4 and 6). In the column 8, the shaft 10 is rotated through an angle of 100 ° from the hydraulic cylinder 9, with the bracket 11 fixed thereon and a pipe 12 welded to it, through which gas is supplied through the gas pipeline to the gas fourteen-mixing injection burner 13. A face shield 14 is placed on the bracket 11 (in the form lid), in which a fourteen-gas injection gas burner 13 operating on natural gas is fixed, as well as a pipe 15 for removing exhaust gases from the furnace space. A swivel frame 16 is pivotally connected to the right 3 and left 4 supports, which in the working position rests on the front 1 and rear 2 curbstones. Mounted on the pivoting frame 16: a lined flask 17 with a gear ring 18 fixed thereon and two support rings 19, with each support ring 19 resting on two support rollers 20. The pivoting frame 16 is welded. The lined flask 17 rotates around its axis. The rotation drive of the lined flask 17 is mounted on a rotary frame 16 and consists of: an electric motor 21, a gearbox 22 and a gear wheel 23, which engages with a ring gear 18 mounted on the lined flask 17. So, two are mounted on the rotary frame 16 in front, two behind the supporting lined flask 17 of the roller 20, rotating in the bearings of the brackets 24, mounted on the rotary frame 16. The furnace has a mounted receiving lined chute 26 with handles mounted on the trolley 25, moving on the trolley 25 along the rails 27 to the lining the flask 17 and vice versa using a hydraulic cylinder 28. The rails 27 are laid on the floor of the workshop, and the hydraulic cylinder 28 is in two cages 29, which are attached to the rack (not shown), and the last to the floor of the workshop. Power cylinders operate from a hydraulic pump station (not shown). The lined flask 17 has a housing 30 of a thickness of 8 mm, welded from steel. A heat-insulating layer is introduced into the lined flask 17, which consists of two layers of a flexible heat-insulating fiberglass mullite-siliceous cardboard 31 and a layer of chamotte lightweight 32, onto which a lining layer of mullite non-shrink packing material 33 with a skull crust 34 is stuffed (Fig. 5). The sheets of the first layer of flexible heat-insulating fiberglass mullite-siliceous cardboard 31 with a thickness of 6 mm are glued with sodium liquid glass to the inner surface of the lined flask 17, Dry naturally until the sodium liquid glass dries. The second layer of flexible heat-insulating fiberglass mullite-siliceous cardboard 31 with a thickness of 6 mm is glued with sodium liquid glass with the addition of 0.5% phosphon on the inner surface of the first layer. Natural drying for 2-3 hours. After drying of two layers of flexible heat-insulating fiberglass mullite-siliceous cardboard 31, a layer of lightweight brick of the ШЛ-0.9 grade is lined according to the template. As a binder, a refractory solution is used, consisting of refractory clay (20%), fireclay powder (77%), water glass (1%), and phosphon (AHFS 2%). The thickness of the seams is 1-2 mm, thermal expansion joints are not laid out. Further, according to the template, a lining layer is composed of a mullite non-shrink packing mass 33 with the addition of 0.2% phosphon. The initial drying and calcination is carried out by portable burners, and then the furnace is calcined according to the calcination schedule. The resistance of masonry and ramming mass is relatively high - 320-420 heats. I propose to further increase the resistance of masonry and ramming mass by treating the new lining of the furnace with AKF-S flux when the lining is heated to 900 ° C. It is important to note that the AKF-S flux must be evenly distributed throughout the furnace lining with a shovel. AKF-S flux penetrates into the pores of a mullite non-shrink packing mass with the addition of 0.2% phosphon and forms a solid glassy layer (skull) on its surface, which increases the service life of the lining and does not adversely affect the furnace lining. In addition, the treatment prevents the formation of linings and slag growths on the lining (verified by experiments and practice).

The introduced heat-insulating layer, which consists of two layers of flexible heat-insulating fiberglass mullite-siliceous cardboard and a layer of chamotte lightweight, laid on a phosphon, can reduce heat loss to the environment, and also allow you to further maintain the temperature of the metal in a rotary inclined furnace for processing non-ferrous metal waste. The AKF-S flux is designed to process a new lining of all types and to prevent the lining from overgrowing from accretions and slag growths.

The service life of the furnace is increased due to the use of mullite non-shrink packing material with a crust crust, which has high fire resistance and resistance.

As a full-time device burner, a gas 14 mixing injection cylindrical burner is used, which has a divider that includes: axis 35, which is mounted on the regulator 36 with a nut 37 and a spring washer 38, and a cone 40 is attached with two nuts 39 from the bottom (Fig. 7, 8). Axis 35, cone 40, nuts 39 are made of VT18U titanium alloy. Studies conducted in the laboratory of Penzaplav LLC in the city of Penza showed that when burning a gas-air mixture an oval-shaped swirl torch is formed, having a length of 2.2 m. A device for controlling air flow consists of: two steel brackets 41, a regulator 36, two bolts 42 , two nuts 43 and two spring washers 44. A device for regulating air flow allows the burner to be used for various compositions of natural gases. To stabilize the flame burning, a stabilizing tunnel 45 is provided. The burner contains a casing 46 welded to a cylindrical gas distribution chamber 47, and into which a refractory packing mass 48 is packed. Each mixer 49 is a cast from heat-resistant cast iron ЧХ22 and is a pipe with a diameter of 58 × 10 mm, which four nozzles 50 are drilled around the periphery at an angle of 25 ° ± 1 ° to their axes with a countersink of the inlet part of 0.5 mm at an angle of 90 °. To fasten the burner to the burner shield 9, a ring 51 is welded to the burner (not shown on the burner). The titanium alloy for the divider, the heat-resistant cast iron used as a material for the manufacture of mixers, and the cast flame-stabilizing tunnel allow to increase the life of the burner and, of course, the furnace. The burner is installed obliquely at an angle of 15 ° to the axis of the lined flask 17. The burner operates at a pressure of 0.08 MPa, the nominal heat output of the proposed burner is 1.9 MW.

The flue gases released during the melting and pouring of liquid metal enter the suction probe 52 and are then cleaned of harmful substances and dust. The loading hole is placed at the end of the lined flask 17, and molten metal is discharged through the edge of the lined flask 17 into the attached receiving lined chute 26 through which the casting conveyor 53 flows. The charge is loaded into the furnace using a vibro-loading machine 54 moving along the track 55 It should be noted that it is necessary to load scrap into the melting furnace, crushed by a grinder (shredder) and subjected to magnetic separation (for separating cast iron and steel in the form of bushings, inserts, pushers, spiers nuts, fingers, etc., which are in the engine scrap.

At the same time, the furnace for processing non-ferrous metal waste is made with the possibility of working on natural and artificial draft with a dust and gas cleaning system to achieve an environmentally friendly process, which includes: a mixing chamber, a smoke exhaust, a gas cleaning unit, an ejector scrubber. Natural draft is performed in case of repair of individual units of the dust and gas cleaning installation. To dilute flue gases with the air of the workshop in order to lower the temperature, before mixing them into the smoke exhaust, a mixing chamber 57 is installed on the pipe 56, which has two gates: one gates regulates the draft (vacuum in the furnace), the second gates regulates the flow of workshop air (not shown). A DN-9u pos. 58 smoke exhauster is installed in the dust and gas cleaning system, which delivers flue gases diluted with air to the gas cleaning unit. The gas cleaning unit is a prefabricated steel cylindrical-shaped body 59, in the lower and middle part of which there are rotary loading grates 60 with holes (figure 2). Above the loading grilles 60, loading nozzles 61 are located. At the top of the cylindrical body 59 there is a cover 62, which is fastened with eight bolts and eight spring washers to the inner flange of the body of the gas cleaning unit. The gas cleaning unit is serviced from ladders. The gas treatment unit is supported by four supports 63. The spent adsorbent and dust are collected in the conical part 64 of the steel cylindrical body 59. The cleaned gases from the furnace are fed to the gas treatment unit through the inlet pipe 65. The principle of operation of the gas treatment unit is as follows: from the furnace, flue gases are pumped by a smoke exhauster 58 an adsorbent layer passes into the inlet pipe 65 and under pressure, a "fluidized bed" is formed, as a result of which the harmful substances in the flue gases are adsorbed by the adsorbent: hydrated lime, silica gel m, birch and activated carbon. The spent adsorbent is collected in the conical part 64 of the body of the gas treatment unit and is discharged through the lower neck and discharge pipe into a metal container 66 and is taken to a dump. The degree of purification of flue gases in the gas treatment unit of a five-ton furnace is: for hydrogen fluoride - 75%, for copper oxide - 87%, for carbon monoxide - 90%, for nitric oxide - 89%, for aluminum oxide - 91% (measurements were carried out by a specialized laboratory at Industrial Casting LLC, Penza).

After cleaning the flue gases from harmful substances, they are cleaned of dust in an ejector scrubber. The ejector scrubber is a steel body 67, with three Venturi ejector tubes 68 placed inside it, into which gases from the gas treatment unit enter through a pipe 69 due to the ejecting action of the irrigation fluid. Irrigating liquid is supplied under pressure of 100 N / cm ^{2 by} pump 70 from reservoir 71 to nozzle 72. Nozzle 72 sprinkles finely sprayed water in the confuser 73 and in the mixing chamber 74 dust particles and in the diffuser 75 they fall into the sump 76, and the purified gases are discharged through the chimney 77 to the atmosphere. Wet dust is periodically removed from the sump 76 and taken to the dump, and clean water from the sump 76 is poured through the pipe 78 into the reservoir 71.

The furnace operates as follows.

The mixture ground on the shredder passes magnetic separation and is fed into the vibro-loading machine 54 by a conveyor belt (not shown), the drive for supplying and removing the burner shield 14 with the gas injection burner 13 is turned on, and the face shield 14 with the gas injection burner 13 is removed, the loading hole opens .

Vibro-loading machine 54 moves along the rail track 55 to the furnace and its tray enters the loading opening of the furnace. The rotation drive of the lined bulb 17 is turned on, as well as the vibration mechanism of the vibro-loading machine 54, and the charge falls into the pre-calcined furnace along the tray. After loading a portion of the charge, the vibro-loading machine 54 moves off for loading, the loading hole is closed, the gas injection burner 13 is ignited. The flame of the gas injection burner 13 hits the inner wall of the lined flask 17, heating it and the air in the lined flask, scrap in the furnace to the melting temperature . Metal melts and accumulates in the furnace. After the molten scrap loaded into the furnace is completely melted, the liquid metal is treated with flux and the laboratory confirms the spectral analysis of the grade of the alloy obtained, the auxiliary receiving lined chute 26 with handles for casting is fed by the hydraulic cylinder 28. The working fluid is supplied to the hydraulic cylinders 7, the rotary frame 16 with the lined flask 17 rotates, while the liquid metal flows along the attached receiving lined groove 26 and fills the molds of the casting conveyor 53. It is important to note that when the furnace is operated on artificial draft, when the gate 79 is closed, and the gate 80 is open, the combustion products passing through the mixing chamber 57 are diluted in it with the air of the workshop, then the exhaust fan 58 is fed to the gas purification unit (the adsorbent is preloaded into it). Flue gases in it are cleaned of harmful compounds in a "fluidized bed" on two rotary loading grilles 60, and enter through the pipe 69 into an ejector scrubber to clean the combustion products from dust particles. Further, the flue gases through the chimney 77 are removed into the atmosphere. Flue gas cleaning makes the process environmentally friendly.

The operation of the furnace on natural draft is carried out if the dimensions of the sanitary protection zone allow, as well as during repair and maintenance work at the dust and gas cleaning installation.

The gate valve 80 is closed, and the gate valve 79 is open, in this case the flue gases directly through the pipe 81 enter the chimney 77 and, further, into the atmosphere.

Claims (2)

1. A rotary inclined furnace for processing non-ferrous metal waste, containing a lined flask with two support rings, each of which is supported by two rollers, a burner shield with a gas burner, a receiving chute, a rotary drive of the furnace and a drive for supplying and removing the burner shield, characterized in that the lined flask has a heat-insulating layer consisting of two layers of a flexible heat-insulating fiberglass mullite-siliceous cardboard and a layer of chamotte lightweight, on which a layer of a mullite non-shrink lining is packed body mass for the formation of a crust crust, a gas injection burner with fourteen mixers mounted in a burner shield containing an air flow control device installed with a slope of 15 ° to the axis of the bulb and providing a torch length of 2.2 meters with the possibility of feeding is used as a burner device gas to the burner along the upper part of the rotary column and the nozzle, while the furnace has an attached lined receiving trolley mounted on a trolley with handles, moving on a trolley along rails to lined flask and back with a hydraulic cylinder, the rotary frame in the working position is supported on the front and rear curbstones, the lined flask is placed on the rotary frame with the possibility of rotation around the axis from the drive containing the electric motor, gearbox, gear, and the furnace is made with the possibility of work on natural and artificial draft, with a dust and gas cleaning system to achieve an environmentally friendly process, including a mixing chamber, smoke exhaust, gas cleaning unit and ejector scrubber. 2. The furnace according to claim 1, characterized in that in the injection burner the mixers and the cast flame-stabilizing tunnel are made of 4X22 heat-resistant cast iron, and the axis, cone, and divider nuts are made of VT18U titanium alloy.

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